Influence of ε-martensite and austenite on mechanical properties by intercritical annealing in 0.1C-11Mn medium manganese steel

• Published in: Materials letters 2022-02, Vol.309, p.131345, Article 131345
• Main Authors: Zhao, Yan, Yang, Dengcui, Mo, Zhiying, Yin, Xiandong, Li, Feng, Yang, Yuebiao, Wang, Shuai, Zhao, Zhengzhi
• Format: Article
• Language: English
• Subjects: Annealing; Austenite; Electron backscatter diffraction; Electron microscopes; Grain boundaries; Intercritical annealing; Manganese steel; Manganese steels; Martensite; Materials science; Mechanical properties; Medium manganese steel; Microstructure; Phase transformation; Phase transitions; Yield strength; Yield stress; ε-Martensite
• ISSN: 0167-577X; 1873-4979
• DOI: 10.1016/j.matlet.2021.131345

•A low-cost and simplex 0.1C-11Mn steel with excellent strength was designed.•TRIP effect, annealed martensite and ε-martensite were introducted.•The formation of ε-martensite and its impact to mechanics were analyzed.•ε-martensite might influence yields strength. We studied the effect of microstructure by intercritical annealing of medium manganese steel in aspect of mechanical properties. The microstructure and phase transformation was characterized by using scanning electron microscope, electron backscattering diffraction and transmission electron microscope. The experimental results showed that ε-martensite appeared as acicular at the austenite grain boundary and phase interface. The volume of ε-martensite and austenite firstly increased then decreased with the increment of intercritical annealing. The yield strength also showed a similar trend in correspondence with ε-martensite. Therefore, in addition traditional strengthening mechanism and austenite, ε-martensite may affect the yield strength.